In the twelfth century the beautiful church and monastery of Chiaravalle, near Milan, were erected by the Campionese Masters, on the commission of the noble family of Archinto of Milan. It is a fine specimen of Italian Gothic, with the dome peculiar to that style. The Visconti of Milan were large patrons of the Campionese school. The fine castle at Pavia, built in the time of Galeazzo II., shows by its style the Comacine hand. It has been assigned to Niccola Sella from Arezzo and Bernardo of Venice, but, as Merzario shows, these men only came to Pavia thirty years after it was finished. The first stone was laid on March 27, 1360. The archives have been searched in vain to find the architect's name: it is, however, proved that Bonino da Campione was in Pavia in 1362, working at the Area di S. Agostino, so it is probable that some of his brethren of the Campionese school were also employed by Galeazzo. Unluckily, these are so individually sunk in the company, that one rarely gets a prominent name. Merzario, quoting other writers, attributes to the Campionesi that sepulchral monument of Beatrice della Scala, now in the church of S. Maria at Milan; the mausoleum of Stefano Visconti in S. Eustorgio, and that of Azzo, son of Galeazzo I.; but beyond a tradition that Bonino da Campione sculptured the last, there is no positive proof.[152] Great conjectures have been made as to the real author of the Arca di Agostino at Pavia. Vasari says--"La quale è di mano _secondo che a me pare_ di Agnolo e Agostino, scultori senesi." His expression, "As it seems to me," is not very decisive proof, truly. Cicognara is not more exact. He "wonders that this most grand and magnificent work is not more famous than it is--and thinks it shows the style of the Sienese brothers, but opines it is more likely to be by some pupil of theirs, if it is not by Pietro Paolo and Jacobello the Venetians." This is vague with a vengeance. Merzario, however, proves that there are no documents to show that the Sienese brother sculptors ever came to Pavia, and asserts that the style of the Arca is not at all Venetian. The learned Difendente Sacchi[153] brings more logic and less imagination to bear on the point. The inscription on the monument proves that it was begun in 1362, placed in 1365, and that the accessory ornamentation was finished in 1370. The books of the administration show that the sums paid for its construction amounted in all to seventy-two thousand _lire italiane_.